Hi,
I'm Davis from ASRock HQ TSD.
We provide few ways for you to verify.
1.Please refer below link to clear CMOS and use BIOS default setting.
http:// (see P.21 in user manual)
2.Please only install necessary devices(CPU, fan, one memory, VGA card, power) for narrowing the problem.
3.Please install one memory to every DIMM for try.
4.Please check whether the pins bent in CPU socket.
5.If you have another suitable CPU and memory, please change them for verify.
If the symptom still exist, please provide the detail system configuration to us for further checking.
Thanks a lot !!
ASRock TSD